Mentioned it so might as well post it. In Legion of Three Worlds everyone is shocked kryptonite affected Superboy Prime as it shouldn't have worked. Then we find out Element Lad and his Legion are from Prime's universe....hence why it worked

Don't have images, but Invincible and Thragg finish their slugfest in the sun, and both get SERIOUSLY damaged by it. As in, Thragg is killed (completely destroyed by the sun, and throughout the fight getting badly damaged too) and Invincible is about to die.

Allen on the other hand is able to ignore it (although exposed for way less time, even brief exposure notably damaged Invincible).

So uh, Allen likely could've just won the fight but I'm guessing he wasn't fast enough to get there in time.